System for capturing and converting solar insolation into thermal, kinetic and electrical energy

ABSTRACT

A selective/reflective solar screen, shade and panel system includes a woven material that creates a plenum between itself and a building envelope. The woven material may selectively admit solar energy into the plenum during the winter months and block the solar energy from it during the summer months. The system captures the solar insolation between the woven material and the building envelope so that it can be used as a source of renewable energy for heating the building. This air can be vented to the exterior so that the building envelope is shaded from the summer sun, which offers a substantial reduction in air conditioning costs.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of U.S. Provisional patent application No. 61/284,010, filed Dec. 11, 2009 and U.S. Provisional patent application No. 61/326,463, filed Apr. 21, 2010, both of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to renewable energy systems and, more particularly, to a system for capturing and converting solar insolation into thermal and kinetic energy.

Passive solar energy systems are extremely effective, but are difficult to control during the summer months without an expensive and elaborate shading system. One example of a conventional passive solar energy system is a transpired solar collector mounted a few inches from a building's outer wall. The wall panel includes perforations to allow outside air to travel through the face of the panel. Solar heated air at the surface of the panel is drawn through the perforations where it rises between the two walls and enters the building's ventilation system. This system, however, uses a metal panel to absorb the sun's energy on the surface and does not allow the sun to penetrate beyond the panel's surface.

As can be seen, there is a need for a system for capturing solar insolation that may selectively admit solar energy into the plenum during the winter months and block the solar energy during the summer months.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a system for providing renewable energy comprises a weave adapted to selectively control solar insolation through the weave, the weave being disposed a predetermined distance from a structure to form a plenum between the weave and the structure.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a weave according to an embodiment of the present invention;

FIG. 2 is a front perspective view of a solar energy collection system according to an embodiment of the present invention;

FIG. 3 is a rear perspective view of the solar energy collection system of FIG. 2;

FIG. 4 is a perspective view of the weave of FIG. 1, folded to provide an energy efficient orientation;

FIGS. 5A through 5D are perspective views of solar energy collection systems designed for various heating and cooling conditions;

FIG. 6 is a perspective view of a solar energy collection system according to another embodiment of the present invention; and

FIG. 7 is a perspective view of the weave of FIG. 1, encased in a frame, and adapted to generate electricity due to a thermal gradient.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.

Various inventive features are described below that can each be used independently of one another or in combination with other features.

Broadly, an embodiment of the present invention provides a selective/reflective solar screen, shade and panel system that includes a woven material that creates a plenum between itself and a building envelope. The woven material may selectively admit solar energy into the plenum during the winter months and block the solar energy from it during the summer months. The system captures the solar insolation between the woven material and the building envelope so that it can be used as a source of renewable energy for heating the building. This air can be vented to the exterior so that the building envelope is shaded from the summer sun, which offers a substantial reduction in air conditioning costs.

Referring to FIG. 1, the system of the present invention includes a weave 10 which is typically made of stainless steel, aluminum, copper or the like. The wires of the weave 10 may be “blackened” by, for example, using black anodized aluminum. The weft wires 12 of the weave may move vertically as it moves out and around the warp wires (not shown for clarity) so that the solar cut off angle between the adjacent weft wires is always maintained.

The weave 10 can be pleated as shown in FIG. 4, to maintain the proposed solar orientation, even when a building façade 14 does not face true south. The angle of the pleats may range from a minimum of zero to a maximum of 45 degrees to accommodate all conditions. As the angle from true south increases, the amount of solar insolation striking the building decreases, so there may be diminishing returns for angles greater than 45 degrees. The weave 10 may be turned upside down to convert a 30 degree orientation into a 60 degree orientation, if needed.

A vertical spacing 16 between the weft wires 12 may be determined through a careful analysis of the solar insolation available in a particular location and on the amount of solar insolation needed to heat the building. A design value of zero solar insolation through the weave 10 may be established for June 21^(st), at Noon, to set a base cut off angle and the spacing 16 between the weft wires 12 so that no light penetrates into the plenum space on that day and time. Adjustments may be made to the spacing 16 between the weft wires 12 to increase or decrease the amount of solar insolation entering the plenum space. Increasing the amount of insolation in the late spring also increases the amount of solar heat during the late summer months. As discussed below, this unwanted heat may be vented outdoors to avoid unwanted heat transfer into the interior of the building.

The weave 10 may have the horizontal weft wires 12 travel up, vertically, as they go in front of the warp wires and return to their original horizontal position as they go behind the warp wires. For a latitude like Columbus, Ohio, this vertical travel is about six times the diameter of the warp wires. Therefore, reducing the thickness of the warp wires may reduce this vertical travel. Similarly, crimping the warp wires so that there is no in and out movement of the weft wires 12 may allow the weft wires 12 to remain level-spaced at the June 21^(st) cut off angle.

The weave 10 may be disposed at an angle 18 relative to vertical 20 as shown in FIGS. 1 and 6. This angle may introduce more solar energy into the system and the resulting reduced cross-sectional area of the solar chamber (as discussed below) may increase the velocity of the air as it rises through the chamber.

In certain conditions, such as in northern climates, the weave 10 may be coated so that it creates an air-tight barrier to keep the solar heated air inside the plenum. The coating may be a clear, low thermal conduction coating, such as Nansulate™. Such a coating may transmit up to 100% of the infrared insolation and provide insulation for heat inside the plenum.

The weave 10 may be provided in a single piece equal to the height of the installation, however roll forming the pleats and construction methods make panelization a practical solution. As shown in FIGS. 2 and 3, the width of a panel 22 may be designed to fit a particular installation. Ends 24 of the panel may include furring 26 to encase a plenum 28 formed between the weave 10 and a building (not shown). Standoffs 30 may be provided to help secure the panel 22 to the building. The furring 26 and the standoffs 30 may include rubber gaskets 40 to isolate the furring 26 and the standoffs 30 from both the weave 10 and the building substrates. The furring 26 and the standoffs 30 may be used to adjust the angle (such as the angle 18 shown in FIG. 1) of the weave 10 relative to the building. This angle adjustment may control the depth of the plenum 28. The depth of the plenum 28 may be adjusted to help encourage convection, to control the speed of the air and to reduce noise.

The panel 22 may include lower exterior vents 32 and upper exterior vents 34 to receive or deliver air to the outside of the building. The panel may further include lower interior vents 36 and upper interior vents 38 to receive or deliver air to the inside of the building. The function of these vents will be discussed in greater detail below, with respect to FIGS. 5A through 5D. As discussed below, the vents may include damper boxes for controlling the air flow either to/from the interior or to/from the exterior of the building. The damper boxes may include an electronically controlled damper 42.

Referring now to FIGS. 5A through 5D, various modes of operation of the panel 22 are shown. In FIG. 5A, a heating mode using recirculated air is shown, where air is taken into the plenum 28 through the lower interior vent 36 and expelled into the building 44 through upper interior vent 38. The weave 10 is removed from this figure for clarity. In FIG. 5B, a heating mode using fresh air is shown, where air is taken into the plenum 28 through the lower exterior vent 32 and expelled into the building 44 through the upper interior vent 38. While FIGS. 5A and 5B show exclusively using recirculated and fresh air, respectively, the damper 42 may be controlled to provide any combination of recirculated and fresh air. Similarly, the upper vent damper may be controlled to direct an appropriate amount of heat into the building 44 and direct unwanted heat to the exterior. In the heating modes of FIGS. 5A and 5B, a temperature change of 30-45 degrees is not uncommon in southern regions of the United States.

In FIG. 5C, a ventilation mode is shown, where air is taken into the plenum 28 through lower interior vent 36 and is expelled through the upper exterior vent 34. In can be appreciated that the lower interior vent 36 may be disposed at a ceiling level inside the building to expel warm air from the interior of the building 44. Similarly, in the heating modes of FIGS. 5A and 5B, the upper interior vent 38 may be disposed near a floor level inside the building 44 to expel warm air into the interior of the building 44. In both cases, convection of air inside the building 44 is encouraged.

In FIG. 5D, a shading mode is shown, where air is taken into the plenum 28 through the lower exterior vent 32 and is expelled through the upper exterior vent 34. This mode may be especially useful in the summer to help cool the exterior of the building. In addition, the weave 10 (not shown in FIG. 5D for clarity) may block a substantial portion of the solar insolation from entering the plenum 28 during the summer, further helping keep the exterior of the building cool.

The lower and upper interior vents 36, 38 may be ducted or unducted through the wall or may be ducted to an appropriate location inside the building. In some embodiments, the warm air may pass through a heat exchanger designed, for example, to heat water. This may occur in any of the modes described above.

Referring now to FIG. 6, heat absorbing fins 46 may be installed in the plenum 28 of the panel 22. In FIG. 6, the weave 10 is removed for clarity. The fins 46 may increase the amount of convection and could increase the speed of the rising air through the system. Front edge diverters 48 may be disposed between the fins 46 to promote additional head exchange and to also force rising hot air towards the interior of the solar web chamber/plenum. This configuration may be especially useful when the weave 10 does not include a coating thereupon. A micro-turbine tray 50 may be included near the top of the system, as shown in FIG. 6. The micro-turbine tray 50 may include a plurality of micro-turbines turned by the kinetic energy of the rising air before it enters the building. The micro-turbines may be useful to drive a generator (not shown) for electricity generation or to power a water pump (not shown) for circulating water into a heat exchanger (not shown) disposed in the warm air flow.

A small booster fan could be included at the base of the unit to increase air flow through the plenum. The fan could be powered by a photovoltaic panel disposed on or near the unit. Thermometers and anemometers can be installed in the plenum to monitor the production of renewable energy. The data from these sensors can be communicated wireless, for example, to a computer.

Referring to FIG. 7, a panel 70 may include the weave 10 disposed within a frame 72. The frame 72 may be electrically divided into two sections by inserting insulators 74 at two opposite locations of the frame 72. Due to the temperature gradient in the wires of the weave 10, electricity may be generated between each of the sections of the frame 72. The panel 70 may generate up to or over about 1 watt per square foot. The circled “V” in FIG. 7 indicates a voltage meter or a voltage draw. While two circled “V”s are shown, the wires may be coupled to provide one electricity output. In an alternate embodiment, the “V”s may represent heat sinks made of a different metal. For example, the weave 10 may be made of stainless steel, the wires 76 may be made of copper and the heat sinks (“V”s) may be made of aluminum. This difference in metals may increase the generation of electricity of the system.

It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. 

1. A system for providing renewable energy, the system comprising: a weave adapted to selectively control solar insolation through the weave, the weave being disposed a predetermined distance from a structure to form a plenum between the weave and the structure.
 2. The system of claim 1, further comprising furring on the sides of the weave to provide at least a partial enclosure for the plenum.
 3. The system of claim 1, further comprising: a lower exterior vent for receiving air into the plenum from an exterior of the structure; a lower interior vent for receiving air into the plenum from an interior of the structure; an upper exterior vent for expelling air from the plenum to the exterior of the structure; and an upper interior vent for expelling air from the plenum to the interior of the structure.
 4. The system of claim 3, further comprising: a first damper for controlling the air intake between the lower exterior vent and the lower interior vent; and a second damper for controlling the air expelled between the upper exterior vent and the upper interior vent.
 5. The system of claim 1, wherein the weave is pleated at a predetermined angle.
 6. The system of claim 1, wherein the weave is disposed at an angle relative to the structure, wherein the plenum has a larger cross-sectional area at a lower portion thereof as compared to an upper section thereof.
 7. The system of claim 2, further comprising standoffs disposed between the weave and the structure, the standoffs adapted to support the weave and maintain dimensions of the plenum.
 8. The system of claim 1, further comprising fins disposed inside the plenum.
 9. The system of claim 8, further comprising diverters adapted to divert air flowing through the plenum toward the structure.
 10. The system of claim 1, further comprising: a frame disposed about the weave; at least two insulators disposed on opposite sides of the frame, the insulators adapted to electrically isolate portions of the frame; and wires extending from the electrically isolated portions of the frame, wherein electricity is generated in the wires due to a temperature gradient of the system. 